The mammalian laboratory will continue to develop a psychophysically based account of somatosensory interactions by utilizing similar stimulus paradigms in studies of both humans and experimental animals to correlate psychophysical and electrophysiological findings. We hope to elucidate the temporal features of these interactions. We then plan to extend these studies of position-sensitive channels to an analysis of submodality and feature selective channels, using these same paradigms to assess the relative independence of such channels and the specificity of their inhibitory actions on each other. In the work on Aplysia we plan to move beyond a description of the specific relationship between individual cells and behavior to an examination of the general rule that relate different patterns of interconnections to specific types of behaviors. In particular, we will examine: 1) the principles underlying the neural control of the main types of simple behavior: graded reflexes, all-or-none response, and fixed-action patterns, and 2) the principles that determine how different behavioral responses are integrated in relation to each other so as to provide for coordinated actions among a set of different behavioral responses. BIBLIOGRAPHIC REFERENCES: Carew, T.J. and E.R. Kandel. Inking in Aplysia californica: I. The neural circuit of an all-or-none behavioral response. J. Neurophysiol. 40:692-707, 1977. Carew, T.J. and E.R. Kandel. Inking in Aplysia californica: II. The central program for inking. J. Neurophysiol. 40:708-720, 1977.